On a quest for the mead of wisdom

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If you’ve been following along – and of course you’ve been – you’ll have realized by now that I can get sidetracked by the details. Fall down rabbit holes. Go off on lengthy tangents that few people truly care about. Belabor the point. Beat a dead horse. Drive a joke into the ground so far that it comes out the other side at near escape velocity, sinks into a low orbit, passes funny 7 more times, and eventually makes landfall in an unassuming country bumpkin’s backyard in a fiery cataclysm that obliterates any semblance of joy or amusement said joke may have once imparted – and removes all other sorts of enjoyment with it.

I apologize for nothing. As is tradition.

However, I’ve realized more and more that I might want to make my brewing research somewhat more…approachable. My initial foray into simplification has been fairly successful – though it does take some commitment to peruse a poster and a number of references – but it’s always worthwhile to try new approaches.

In other words, I need to make this doable without digging kilns and drying malt with horse shit.

I know, I know, gentle readers – who doesn’t love picking over dead languages in pursuit of a pint? But information that cannot be digested by its audience is of little value – the bran muffin of the intellectual world. Boring, tasteless, and probably good for you – but seriously, blueberry is so much better and really the bran is just there to remind you of the better things in life, right?

Right, right, tangents. Back to business. Here, I will present a summary of the Viking-era brewing process I’ve cobbled together in some more specific detail; following that, I will present several ways that you can implement the principles without drifting too far from your comfort zone.

I am, after all, very concerned with your comfort.

HE’S BAAAAAACK!

The Viking Method Summarized

1.) The Grains

Archaeological evidence suggests that the dominant cereals among the Norse included barley, oats, rye, and wheat in some locations. “Bread” finds from a number of Viking-age sites show that grains were often combined together. In addition, legumes and vetches were sometimes seen in conjunction with cereals.

Barley is the dominant grain type by far, and has been found as far north as Iceland and Greenland, indicating widespread intentional cultivation of the crop. 6-row barley seems to be found exclusively; a cultivar named “Bere” is believed to be descended from Viking-era barley crops.

Grains were probably sown in the spring and harvested not too long after – many landrace 6-row barleys can reach full maturation in 90 – 100 days. Grain would likely have been processed for storage soon after harvesting.

2.) The Processing

Malting was likely rooted in a form of grain processing that was originally intended to de-husk the grains. Grains would be soaked in water and then dried, allowing the husk to be removed easily. Such a method is also reflected in a fragmentary writing attributed to Zosimos of Panopolis, where a method of de-husking grain involves a few days of soaking in water.

The Senchas Mar, an 8th century Irish legal text, includes a detailed method for the malting of grain. This technique may have been passed along routes of cultural transmission to the Scots, who had contact with the Vikings – indeed, there were many Norse settlements in northern Scotland. A book on Norwegian farmhouse brewing traditions includes information about malting techniques purportedly derived from Viking tradition. In both cases, the processing is essentially the same: grains are steeped, heaped, allowed to sprout, and dried by a fire. The process takes 9 – 12 days depending on your specific method.

Corn-drying kilns in Scotland have been discovered. Fuels include local hardwoods, grasses, dung, and peat. Grains were probably soaked and dried en masse not too long after harvesting, to assist in processing.

Quern finds from Jorvik demonstrate the ability to generate flour. The technique in the Senchas Mar discusses turning the malt into “cakes;” it is plausible that the Viking-era “breads” which are found in the archaeological record are the result of this malting process. The flour would be mixed with water – possibly seawater – and formed into small unleavened biscuits which were dried over a fire.

As noted above, some of the Viking-era “breads” contained oil seeds and herbs. It is unclear when those may have been added, but addition either to the malting or to the grinding of the dried grain both seem plausible. It is unlikely that all grain was fortified, as most bread finds do not include flax or herbs.

3.) The Mashing

The “breads” that would result from processing acted as a method of easily preserving the grains for later use; these would form the “malt” for brewing. There is virtually no evidence pointing to a concrete mashing method employed by the Norse. However, disparate evidence may indicate a method.

Merryn Dineley suggests that structures identified as bath houses may have been brewhouses, and that fire-cracked rocks would have been used to heat liquid contained in wooden vessels. Capacious wooden vessels from the Viking era have been found in the Oseberg burial as well as others. Recent work by Dr. Pat McGovern indicates that heat-treated tree resins (including birch and juniper) were present in beverages from precursor cultures in what would become Viking-age Scandinavia.

A plausible method that joins all of this evidence would be something similar to the Finnish sahti brewing tradition. A wooden vessel (possibly a hollow log like the Finnish kuurna, or else any one of a number of large wooden barrels) would be lined with juniper branches and possibly birch. Grain biscuits and water would be added to the vessel, and hot rocks would be used to gradually heat the batch to near boiling. The liquor would then be drained off to be fermented.

4.) The Product(s)

Two types of beverages would be produced. The first was a common nutritional/medicinal beverage that would be produced with frequency, akin to the “zythum” of the Talmud and other sources. This lightly fermented beverage would double as a yeast propagation medium; the residue of this beverage would remain in a wooden fermentation vessel, and would be referred to as “gruit.”

The second beverage would be a strong alcoholic drink, similar to hydromel. Literary use and linguistic origins relate such a drink to “wine,” indicating a plausible similarity in purpose (sacrament, celebration, mourning, etc). A combination of grain, honey, and fruit was likely collected in a large wooden vessel, and some of the residue of the daily drink was added. This would inoculate the batch with yeast, enabling alcohol production. The beverage was likely sweet, owing to its probably short fermentation time and large collection of sugars.

Herbs (including hops in some locations) may have been added to the drink prior to fermentation. More than likely, the alcoholic version was reserved for special occasions, and its production was a secret known to few.

Um, excuse me, I was told there’d be beer. Excuse me?

Recreating the Past on a Budget

OK, on to the stuff you’re really after – how to do this without reading 1198 rambling words from some pontificating blowhard.

1200, now.

I’ll break the modern version down into the same steps, and go over some possible ways to interpret them easily.

Remember, all steps on the path can be valid. The important thing is to know why you’re making the choices that you’re making, and to document them for review later. It’s an excellent method of learning and developing a process while recreating an ancient technique.

Pick one option for each of the categories below, and plug ‘em together. That will give you your method guidelines. From there, you can feel free to experiment by picking other options on another pass. Or invent your own interpretations! After all, I’m not the be-all-end-all on this topic.

1.) and 2) The Grains and Their Processing

Several options exist.

You can malt your own grain using sprouting barley or whole oats; barley is easier to find. Soak the barley in water for a couple of days (changing the water a couple of times) until it’s fat, then heap it up and turn it periodically until it starts to sprout. Drying the grain can be achieved in a smoker or on a grill using wood and peat (and dung if you’re adventurous). Grinding grain can be accomplished with a food processor – or if you’re feeling adventurous, a concrete rotary quern modeled on historical example. This will produce a coarse flour which can be made into unleavened biscuits.

Optionally, one can use malted barley flour (also known as “diastatic malt powder”) and add some darker crystallized grain to make a biscuit. The stuff is pricey, but if you’re willing to throw money at something to save labor, this method will allow you to make the biscuits in a fairly convincing manner while saving a bunch of work.

Obviously, if you’ve chose to go an extract route, mashing is less important. Still, read on for general principles of recipe construction.

Based on physical evidence and batch sizes extrapolated from writings and serving vessel size, we can conclude that the Norse brewed in batches of at least 6 gallons. The ratio of grain to water is unknown, but based on glosses with “hydromel,” it is reasonable to conclude that the product would have been higher-gravity – in the 1.080 to 1.100 OG range.

This can be achieved by using a thick mash (1 qt/lb) typical of a wee heavy, or can be achieved using a thinner mash that is later supplemented with honey. A proportional recipe would more accurately reflect the processing technology the Norse likely had. An example proportional recipe could be (by volume) 1 part honey, 2 parts grain, and 8 parts water. That’s roughly 60% honey/40% malt by weight. Feel free to adjust the proportion of honey to malt as you see fit, or omit the honey altogether – it was rare and expensive then, and not everyone would have it. Smoked, roasted, peated, and crystal malts are all appropriate choices.

The most likely vessel for mashing would be a large wooden bucket, trough, or hollowed-out log akin to the Finnish kuurna. The vessel would be lined with branches from resinous trees (juniper, fir, and pine are the most common), and hot rocks could be inserted to achieve heating.

A reasonable way to replicate this is to add wood to your normal mash tun (or even just a big pot). Layer the bottom with birch, juniper, pine, and/or fir. Heat rocks in your oven (grill stones or garden stones work very well) and drop them in one at at time, slowly raising the temperature close to boiling. The high-intensity localized heat from the rocks will caramelize the wort, and heat-treat the tree resins.

Most hardware stores and agricultural supply stores will carry wood shavings, chips, and other such products. If you don’t have a source of naturally-occuring resinous wood near you, the store-bought options will suffice in a pinch. Add a good layer of various shavings to the mash and proceed as normal. Hot rocks are still a good idea for mashing.

If all else fails, juniper berries are usually pretty easy to find. Add some to your normal mash routine. Be generous, because their flavor can be subtle against a heavy malt bill. Direct-fire or infusion mashing will be fine, though the wort will probably not be as heavily caramelized and the juniper resins may be harsher.

4.) The Product

Once the mash is finished, you should let the wort cool before running it into another vessel. The Norse probably didn’t boil their wort after the mash – the mash temperature is sufficient to kill most microbes, and boiling would just expend additional fuel. Aside from that, no metal or stone vessels of sufficient capacity are found to permit boiling an entire batch.

The wort was probably fermented using the dregs of fermentation of a previous batch; typically, this would have come from a medicinal/nutritional beverage that was being produced on a daily basis. This product would contain grains and herbs, and often flax or other oil seeds. Tart fruit (wild apples, polar berries, sloe, and others) and honey may have also been added at this point to add additional sugar and flavor; honey was rare and expensive for the Norse, so it would have been a very coveted beverage!

Given the lack of good storage options, the product was likely consumed very young – 3 to 7 days typically, and perhaps up to two weeks at most.

Use a mix of malt, appropriate herbs, and optionally some flax seeds to create a yeast propagation medium. Ferment in whatever’s handy, and add the residue (or the whole liquid if you’d like) to your batch. Give it a few days and you’re good to go! Appropriate herbs include yarrow, arctic thyme, bog rosemary, and bilberry. Hops would also have been available in southern Scandinavia and were probably used like any other flower or herb.

If you’re a brewer, the odds are good that you have a bucket with yeast lying around somewhere during you brew time. Rather than make a specialized starter, you can just dump the beer on an old yeast cake, and sprinkle the herbs on top. They’ll provide flavor and aroma while the old yeast will go to work on the beer. Be careful when re-using old yeast – depending on what they last fermented, they may be stressed and may ferment poorly.

Can’t find weird herbs? We have roughly as much evidence supporting the use of hops in Viking brewing as we do any other herb. Hops appear less frequently in finds, but they do exist. Most finds are limited to southern Scandinavia. Get yourself some whole-leaf German noble hops and use them to dry-hop the product; use about 2 grams of dried hop per pound of fermentable. Bittering hops are probably not appropriate for a Viking brew (that’s what the tree resins are for). Use whatever yeast you normally would.

And there you have it! The shortcut to Viking-era beer! Now go forth and make your ancestors proud!

So it’s been a little while since I last wrote an entry. Fear not! I’m still plugging along, brewing crazy things and writing weird poetry and telling stories about people who kill other people over beer. Good things all around! I’ve just had a double helping of Life and Such, and so things have gone off track.

Enough excuses. Back to writing.

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A couple of weeks ago, I followed up on an opportunity to talk about historical brewing at a local museum. The event was focused primarily on the history of brewing in the Hudson Valley of New York, but as the museum was also running a piece on ancient Egypt, the program director wanted someone to speak about ancient Egyptian brewing.

Through some various channels, I was tapped to give a brief talk on this topic. Now, it’s not my primary area of research, but mindful readers may remember that I touched on a prospective Egyptian precursor to beer as part of my research on Viking-era brewing. I eventually settled on its existence as being somewhat central to my reconstructed processing technique, representing a yeast starter of sorts that would have been prepared daily as a medicine, and which would result in a healthy yeast culture in the residue.

One of the things I’ve begun to question is the oft-repeated “story” of ancient beer – ancient peoples are often alleged to have drunk a weak alcoholic beverage that was filled with yeast and residual grain. It is sometimes argued that this was drunk in lieu of water (an idea which I and others seriously question, and for which extraordinarily little evidence actually exists), and it is sometimes argued that such a beverage would be an extremely nutritious “liquid bread” (though we also know that ethanol inhibits the absorption of many nutrients).

What I’m going to do here is take you through my talk about a particular Egyptian grain beverage called “zythum,” deconstruct the standard story, and reconstruct a plausible alternative (which is also supported experimentally).

So What the Hell is “Zythum?”

“Zythum” is the Latin equivalent of a Greek word “zythos.” “Zythos” is first seen in the writings of the 1st century BCE Greek historian Diodorus Siculus, who wrote the Bibliotheca Historica. There, he describes “zythos” thusly:

To be fair, neither do I, and that’s why we often must rely on translations of such writings. Here, try this:

The Egyptians also make a drink out of barley which they call zythos, the bouquet of which is not much inferior to that of wine.

The reason I point this out is that the process of translation is not a perfect one – ideas sometimes have difficulty crossing cultural boundaries, and so we must attempt to capture the “sense” of a word. Sometimes this means that we may obscure part of its literal meaning, or we may lose some nuance that is really only understood by the native culture. And of course, English has this nasty habit of grabbing older words from other languages to talk about lots of things – so sometimes we use an older word from another language to talk about a thing that we do, even if our practice differs from the old one. Keep that in mind as we proceed.

OK, so! If we look at this one source, we can see how one might reasonably conclude that “zythos” is an analogue to beer, right? Diodorus compares it to wine on the parameter of its bouquet, so perhaps we could reason that the two must share some commonalities. I mean, why compare it to wine if it wasn’t being used like wine, right? And it’s made of barley, so we have the possibility of an alcoholic drink made of barley. Heck, even the actual word “zythos” gives us a clue as to its nature – it’s closely related to lots of other words that indicate leavening.

So a barley drink that is related to wine and that is leavened? Sounds like beer to me!

But it’s a poor researcher who limits himself to one source. Let’s look for other evidence of Egyptian barley liquids:

For wine, they use a drink made from barley, for they have no vines in their country.

Well, there it is again. We have evidence of a barley drink that is related to wine. Seems that one could draw a line from “zythos” back to at least the 6th century BCE, right? So there we go, reinforcement that “zythos” is beer and it goes back a ways.

Well, not so fast, cowboy. See, “wine” doesn’t have to mean alcohol – that’s our most common sense of the word, but in ancient Greece and Rome, “wine” was used to refer to several different products of the vine. Cato the Elder gives a “wine” recipe in De Agri Cultura that involves diluting the must 1:5, adding seawater and vinegar, and waiting a bit. It makes an excellent vinegar after a fashion. Doesn’t really sound like merlot, does it? And in many places, the juice of grapes is called “wine” as soon as it is pressed – the fermentation doesn’t seem to be the critical factor there. So while Herodotus talks about “wine” and Diodorus talks about “wine,” there’s no guarantee they’re talking exclusively about a strong alcoholic beverage.

Let’s move on. How about Hippocrates, the father of medicine? He wrote an entire treatise on the use of barley in remedies in the 5th century BCE:

Ptisans are to be made of the very best barley, and are to be well boiled, more especially if you do not intend to use them strained.

Fun fact: “ptisan” is etymologically connected to “tisane,” which is a term we use to refer to “teas” made of things that don’t actually involve tea leaves. Neat, huh? Also as a side note: Hippocrates mentions that people routinely refer to various remedies over-broadly, lumping several different things together under a single name. Something else to think about when you read about “wines” made of barley, eh?

But it seems like we’re seeing alternate uses for barley drinks – here, a medicinal beverage is concocted.

How about we jump ahead a bit to one of my favorites, Pliny the Elder, who wrote Naturalis Historia in the 1st century CE. I’ve talked about many of his writings in various places on this blog, but there’s one in particular that is of note here. He discusses a variety of non-wine beverages made from grains:

Different beverages, too, are made from the cereals, zythum in Egypt, cælia and cerea in Spain, cervesia and numerous liquors in Gaul and other provinces. The yeast of all of these is used by women as a cosmetic for the face.

Several things are notable about this statement. For one, the specific chapter in which this is found is in a book that deals with medicinal remedies derived from plants (book XXII). Pliny also discusses “wines” of grain in a completely separate section (book XVIII), and it is clear that these are distinct types of beverages.

“Zythum” is the Latin equivalent of “zythos,” and here we see Pliny discussing it. So now we have yet another possible view of the drink.

One should also note the other listed beverages. Pliny is calling them different things, but sort of lumping them together in the same functional category: a book all about remedies from plants discussing several beverages in the same sentence hints at a similar function. The word “cervesia” is notable because similar words are used to mean “beer” in modern Romance languages. Yet here, it is clearly discussed outside of a “wine” context and in a remedy context.

We also see a common utilitarian purpose; the “yeast” (actually, the word was “spuma,” which means “foam” – one of those interesting translator choices again) is used by women as a facial cosmetic. Such a use may indicate a more frequent production, assuming Roman women were applying facial cosmetic regularly. In order to use it so, there’d have to be enough kicking around frequently enough.

And of course, the mention of “spuma” may help indicate a possibly fermented beverage – but one that is not as strong as wine, and which is used for remedy/utility purposes.

Well, now I’ve done it. I’ve gone and muddied the waters that had previously been clear and over-simplified. While one might be able to look at the evidence for “zythos” and argue for an alcoholic beverage, a more careful look at additional evidence calls that into question. It seems to be related to medicine (and the use of barley medicine is quite old), is noted separately from “wine,” and even the word “wine” may not mean what you think it means.

Many people, in times of confusion or need, have turned to various holy books for guidance. While I don’t normally put stock in such things, it seems that it will take a miracle to resolve this confusion. Let’s see what the gods have to say about this.

“Thou shalt not fruit thy beer, for that is totally lame and only appropriate for yellow swill in clear bottles.”

The Babylonian Talmud contains numerous laws, and in Pesachim 42b, we find this written:

What is EGYPTIAN ZITHOM? — R. Joseph learned: [a concoction made of] a third part barley, a third part safflower, and a third part salt. R. Papa omitted barley and substituted wheat. And your token is ‘sisane.’ They soaked them [these ingredients], then roasted them, ground them and then drank them. From the [Passover] sacrifice until Pentecost, they who
are constipated are relieved, while they who are diarrhoeic are bound. [But] for an invalid and a
pregnant woman it is dangerous.

The specific section in which we find this is a list detailing additional specific items which must be removed during Passover because they are chametz (typically meant as “leavened,” but Jewish law calls grain chametz in many other circumstances). One explanation for such a list is that they are mainly items which may be in the house, but whose manner of preparation is not known to the keeper of the house. Perhaps they are purchased from elsewhere. It would also seem to follow that the products must not be obviously leavened or fermented, or not obviously grain-based – otherwise, it would be obvious to remove them.

Note that a medicinal use again is indicated, and no specific mention of fermentation is made. One could suppose a sort of fermentation may happen (it is in a book talking about taking leavened things out of the house), but grain is chametz when mingled with water for 18 minutes – so it doesn’t have to be fermented.

Well, OK, so it may or may not be fermented. Probably isn’t obviously fermented, and given the high salt content (more about this later), the stuff would have to be fairly dilute to be reasonably drinkable – so it wouldn’t ferment far if it even did. In fact, it seems like the salt may be an attempt to control the fermentation – either it’ll be too salty to ferment but have a lot of calories from grain, or it’ll be too dilute to have appreciable alcohol.

Now let’s try something from the 10th-century Islamic empire. Here’s a recipe for something called fuqa (lit. “bubbly drink”) from a translation of an ancient cookbook:

Boil water, enough for making 50 beer glasses, and pour it on the malted barley. Stir and mix until only barley shells remain. Set it aside to cool down then strain it and take the amount enough for making 50 beer glasses. Add a suitable amount of salt (pure and white rock salt) so that the beer will be neither too salty nor bland. The best way to judge is for the beer-maker to taste it. Set the liquid aside until it settles and looks like clear water.

The recipe calls for ~1.1 kg of malted barley. A “beer glass” may have been as large as one cup (~250 mL) in capacity, so this recipe could be looking to make up to 12.5 L of liquid from 1.1 kg of barley malt – about a 1.022 OG assuming flawless extraction. That’s not very much at all. Also note the salt addition – seems reminiscent of the Talmud method, eh? And of course, the very beginning of the chapter about fuqa talks about the medical use of barley water – so again we have a medicinal context.

Here, you are ultimately instructed to sort of ferment the beverage – you leave it for 12 hours in a jar that was previously used to brew beer. The text warns against using the same jar too many times – it must be discarded once fermentation is apparent. So again we see evidence of a processing technique that may involve a weak non-obvious fermentation of a very dilute beverage.

Christian scholarship may also give us some clues. A 19th-century German scholar of ancient medicine found a fragment of text that was attributed to Zosimos of Panopolis, a 4th century CE Greek alchemist. You may recall that I discussed this before in another post, but I’ll repost the method here:

Take good pure barley and water, and soak it for a day. Spread it out and put it in a windy place for another day. Again soak it for 5 hours, then collect it in a sieve with handles, and soak it again after it has drained until it becomes puffy.

When this is done, dry it in the sun, until it deflates: The husk is indeed bitter.

Now mill (it), and make a bread-dough, adding leaven as in bread-making, and bake it very well. Then boil it well, and separate the sweet water, straining it through a sieve.

Some heat toasted bread in a pan with water, and cook it a bit, but neither must he boil it nor heat too long, and taking it from the fire, transfer to other vessels, and again heat and reserve (the liquid).

So now we’ve got a bread beer thing that also doesn’t talk about fermentation. Sounds an awful lot like Russian kvass, eh?

Hm. Based on my reading of all this information, I’m putting together a different picture than that oft-repeated story about daily beer. What I’m seeing is evidence of a non-or-lightly fermented beverage akin to a kombucha or kvass, probably made with a weak dilution of grain (and possibly herbs) and salt, that was used as a medicine and common drink. A lot like a fermented barley tea.

And that makes sense when you boil it down, doesn’t it? We know that alcohol is a diuretic, and that it lowers blood sugar, and that it has all kinds of properties that make it nutritionally deficient. At least two full processing methods seem to attempt to minimize ethanol production.

Imagine this: you’re the guy in charge of building the pyramids, and you’ve got your team with you (evidence suggests that the pyramids were actually built by skilled laborers and not slaves as previously thought). It’s hot as hell, and they’re hauling really heavy blocks. Do you want them drinking something that will dehydrate them and drop their energy levels, or would you give them a drink that is mostly water with added electrolytes (salt), carbohydrates (sugar and starch from the grain), B vitamins (assuming a light fermentation, yeast will grow and contribute nutrients), and possibly some poorly-controlled medicinal effects (herbs)? Like drinking pickle brine when you’ve been in the hot sun all day.

When you get right down to it, the idea of daily booze doesn’t make sense, and the evidence really seems to support this sort of fermented tea process.

But that’s all talk. How about some experimentation?

Equal parts barley, salt, and safflower (by volume), steeped in water until it was fully saturated, dried as per the method attributed to Zosimos. I was curious about the salt content, so I did a version with salt and another without. Picture 2 is the salted version; picture 3 shows the unsalted version, which began fermenting not too long after being submerged in water. This reinforces the idea that the salt content is at least in part intended to control fermentation.

The mass of stuff I started with in 2 was 134 g; after drying, I had 157 g. The unsalted version gained no mass at all. This indicates to me that the grains took up 23 g of salt during processing – giving a final salt content of roughly 15%.

That’s really damn salty, so I diluted the grains 1:10 as per the method indicated in the Islamic text. That would reduce the salt content in the drink to 1.5% – probably a manageable level. I also wanted to know about fermentation or not, so I did a Punnet square: salted/unsalted and fermented/unfermented.

What I discovered is that the beverage didn’t generate any alcohol at all, not even after days of fermentation. It did encourage yeast growth, and the salted/fermented version tasted something like chicken soup after about 24 hours. The unsalted version were flat and boring, but the salted version were pleasantly full – not quite as strong as pickle brine, but definitely filled with electrolytes. After enough time, the fermented versions became somewhat sour, but not unpleasantly so.

Really, this is like an ancient form of Gatorade. It’s all manner of not bad, and I highly recommend trying it! The high salt content seems to necessitate an extreme dilution of the stuff, and if it was being consumed every day, it really wouldn’t have time to make alcohol. When post people think of a “low alcohol” beverage, they mean 2 – 3% ABV, but I am talking about a drink that is literally non-alcoholic – probably under 0.5% ABV.

The most interesting part of all of this is the connection to other words that we translate to mean “beer.” I’ve used that connection to suggest that this processing method carries forward into Viking-era brewing – a grain/herb mixture fermented frequently, whose residue could be used to start a strong beverage. Makes sense, right? You’ve got a yeast propagation medium with a strong connection to health and cleanliness – seems like the kind of thing that would make a pure beverage, right?

And maybe this technique carried into the Germanic tribes outlying Rome, and maybe some brewers out there saw some pretty flowers growing around a tree and thought, “Man, I bet those would go well in that grain tea I love so much.” Maybe that’s how hops entered the equation all those years ago.

Of course, none of this analysis precludes an alcohol interpretation, either. “Wine” can mean a lot of things, and that includes wine. So maybe there were several traditions that existed at the same time. Maybe the daily beverage existed and a strong beverage was made as well, and both were called “zythos.” Hey, Bud Light and Sam Adams Utopias are both “beer,” right?

This is why we have to interpret archaeological evidence, and consider the paradigm under which we are operating – because sometimes we bring our modern biases into history, and they just don’t belong there.

I’ve talked at you all before about how easy it can be to do historical brewing research and recreation. We often attempt to take the principles of period processing methods and attempt to translate them into modern methodology, to give a sense of historical practice by varying the familiar.

We can also alter ingredient bills, to attempt to emulate the flavor profiles that may have existed at the time. This is all well and good, and it’s an important part of the process of experimental recreation.

Sometimes, though, the task is not so clear-cut, and attempting accurate recreation becomes a real challenge. How were the ingredients grown? What units of measurement were at play? Water quality? We can’t always answer all of these questions, but the attempt to do so can yield valuable information, and the process of extrapolating will teach us things whether or not we get a useful end-product.

So let’s talk about wood.

SEE WHAT I DID THERE?(Archaeological Museum of Baden-Württemberg. Photo: Manuela carpenter – click for a link to the gallery page)

This bottle is part of an excavation of Trossingen grave 58, a find in Germany that dates to the 6th century CE. The picture above links to a gallery of the find.

This bottle is identified as a vessel with the remains of a hopped barley beer. This is sort of A Big Deal in the historic brewing world, because this would constitute the oldest existing physical evidence of the use of hops in a fermented beverage ever found. Not only that, but this is solid physical evidence of the use of hops a good 500 years before we had thought hops were really coming into use. This find has the power to really re-shape what we think of the history of brewing and hopped beverages. Neat stuff.

There is a publication which details the find (and its numerous artifacts) which you can obtain here; of course, the entire thing is available exclusively in German, so you may have to find a linguistically-inclined friend to help you out with it. Fortunately, I have some connections, and I managed to acquire the part of the journal detailing the bottle find. A bit of OCR, Google translate, dictionary consultation, and linguistically-inclined friend consultation, and I managed to figure out most of what the find was about.

Evidently, there was pollen residue in the bottle (~3500 grains), and researchers were able to identify the sources of the pollen grains:

If my translation is right, the contribution is 17% barley, 11% cereal weeds (possibly rye or oats?), 0.4% hops, 0.4% grapes, and 29% “bee pollen” (which is taken as a marker of honey). The bottle also contained evidence of fermentation (oxalate crystals), and so the author concludes that the beverage was probably a mixture of the above ingredients in the mentioned proportions, fermented together and hopped. The beer came first, and it was “enriched” with honey – or so the author concludes.

But I don’t like that analysis. For one thing, the author doesn’t seem to try to figure out the actual proportions of the plant matter represented by the pollen; the text seems to assume that all ingredients will convey the same amount of pollen, which may not be the case. They also don’t elaborate too much on their rationale for their experiments or on the type of hop present – which is too bad, because this is a pretty big find!

So let’s tear this down and show how you can extrapolate a recipe from scant information. What if you wanted to try recreating a beverage like this? No recipe, no method, just some pollen grains in a bottle – how can we do it?

Watch and learn.

That feel whenever you take off autopilot and try to land the science jet yourself.

When we do this kind of analysis, we often have to make lots and lots of assumptions and extrapolations. In archaeology, the variables are often well beyond our control – so experimental archaeology must try to control what it can or accept the limitations of uncontrolled variables. I’ve advocated a sort of “mapping” approach to redacting and analyzing ancient recipes, and that principle will aid us here as well; by listing out my assumptions and reasoning, I can go back and nitpick and refine and strengthen my arguments.

The goal here is to get to something that resembles a more accurate technique, and in the process to enumerate some other possible and plausible methods. Most of the time, these sorts of analyses are rarely definitive, and tend to leave us with more questions than when we started – but it helps us to focus our inquiries, so that our questioning can be more productive. This is the heart of science.

Let us assume:

1) That a total of 28% of the 3500 pollen grains are attributable directly to barley which has been malted (that would be 17% attributed mostly to barley and 11% attributed to “cereal” weeds – we know that barley is not generally insect-pollinated, so the “bee pollen” probably does not cross with this group);

2) That 29% of the pollen grains are attributable to raw honey (bee pollen shows up often in raw honey);

3) That 0.4% of the pollen grains are attributable to Hallertau hops (they’re alleged to be the first hops that were ever domesticated, and the Trossingen area was close-ish to Hallertau);

4) That 0.4% of the pollen grains are attributable to grapes (though as you will see shortly, I haven’t rolled grapes into my analysis yet because I can’t find information about them);

5) That the ingredients were fermented together in a single beverage (as opposed to the pollen contribution coming from, say, 3 different beverages which all touched the bottle at some point);

7) That a single kernel of dry barley weighs one grain (0.06 grams – the origin of the term “grain” is the weight of one kernel of barley), and that malted barley is ~10% less dense than unmalted barley;

9) That hops used were wild, and thus grew at a ratio of 1:1 male:female plants (hops are a dioecious plant, and wild-type examples of such plants grow in a ratio pretty close to 1:1 – this indicates that the pollen load of a male plant reported represents a single female flower);

10) That hops pollinate in a manner similar to their nearest botanical relative, Cannabis (note that hops are a cannaboid) – which produces an average of 36,500 pollen grains per male flower;

11) That the mechanism of wind pollination results in ~95% of the pollen accumulating on the windward (i.e. exterior) surfaces of the plant, and that this pollen load would be removed in hop processing (i.e. the pollen that didn’t make it into the interior of the female flower just falls off);

12) That there are 100 wet hop flowers (we use the female flower of the hop in brewing) per 50 grams of hops, or 0.5 grams wet per hop flower (which translates to roughly 0.1 grams per dried flower);

13) And that these estimates actually apply to 6th century German plants.

Y’know, I never noticed the completely incredulous look on his face until right now.

So, basically, I’m making shit up. “Educated guesses” if you’re feeling generous – but I’m basically winging it in the absence of any more useful information.

One thing that we can definitely see by my analysis so far: it is a great mistake to assume that all of the ingredients going into a beverage would have the same pollen representation per gram.

Let’s look at my numbers. Each barley grain produces 2250 pollen grains, each gram of honey has 6000 pollen grains, and each hop flower has 1825 pollen grains (5% of 36.5k). Let’s convert these to a standard measure: pollen grains per gram of plant matter.

Barley: 37.5k pg/g
Honey: 6k pg/g
Hops: 3650 pg/g

Now, how about the proportional representation of pollen grains in the find? 3500 pollen grains total, so:

Barley: 28% = 980 pg
Honey: 29% = 1015 pg
Hops: 0.4% = 14 pg

And then we just do the math to figure out the possible mass of plant matter that delivered that pollen load!

Barley: 0.026 g
Honey: 0.17 g
Hops: 0.0038 g wet (1/5 as much dried)

That gives us a ratio of barley:honey:wet hops (by weight) of 26:170:3.8, or to make things easier: 7:45:1

So let’s turn this into amounts that make more sense, shall we? Let’s also not forget that malted barley weighs 10% less than “green” barley:

The first thing I notice straight away – this ain’t a barley beer. Not by any stretch. The mass of barley is so small that it really seems much more like a flavoring or additive than anything else. The vast majority of sugar here is coming from the honey – enough that I’d really call this a “mead.”

Of course, as you will remember, the word “beor” (which is a root of “beer”) is glossed with “hydromel,” which refers to a honey-based strong beverage. So really, it’s not outside the realm of possibility that one could call a honey-based drink a “beer” in the ancient world – it seems to have fulfilled that role.

Pliny specifically discusses the various methods of making “leaven,” and one method is to incorporate grape must into barley flour and make a biscuit. Grape must incorporated into such a “bread” as I’ve talked about previously could explain the grape pollen in the original find. The use of herbs in the bread may give us a clue as to how the hops came into play; perhaps grape must and hops were mixed into barley flour, and the resultant “cake” was used as a yeast starter to then ferment a honey/water solution.

We can make a wide number of recipes simply by varying the amount of water that goes into such a thing. Generally, “hydromel” was a 1:4 honey:water ratio. A pound of honey occupies a space of about 10 fluid ounces, so we’d need about 40 fluid ounces of water to properly dilute that honey. Do that, add in your 65 grams of barley/dried hop mix (which has been previously fermented), and wait a bit. Yeast from the grapes eat those sugars, and you get a little more than a quart (about 1.5) of slightly hopped mead.

How hopped? Well, 2 dried grams of hops at that density of sugar yields ~12 IBU – roughly the same bittering content of Budweiser. For reference, an English Ordinary bitter is somewhere in the 25 – 35 IBU range. American pale ales are in the 50’s, and IPAs are up in the 70’s or more.

You could even add a bit more water – maybe go to half a gallon of final volume (1:5 ratio) with all that honey, which would give you a lighter-bodied beer with only 8 IBU. A little less sweet, a little less hoppy. The evidence still supports such an idea. Hell, it supports a lot of ideas.

Or you could go heavier (1:3 ratio) and make something really sweet with about 16 IBU. It’s all up to you and what you prefer!

Therefore, based on my analysis of the evidence, I conclude that the Trossingen bottle may have contained the remnants of a lightly hopped mead, which may have been fermented using the residue of a light grain fermentation.

The lesson here: archaeological evidence always requires interpretation. Using the same set of facts, we can come up with very different conclusions simply by varying the manner of our interpretation and the set of assumptions used to perform an analysis.

This is far from a definitive answer. I have thirteen listed assumptions, any variation on any of which can completely alter my outcome. I have no idea how much water was added, or how long it was fermented, or what proportion the grapes represent. We could re-analyze the model with an attempt to figure out what “cereal weeds” means and re-evaluate the contribution of plant matter from those (here’s a hint: rye produces ~10x the pollen that barley does – so there may be even less grain in this recipe than I’ve indicated).

But at least for now, I have something to work with – and that’s how science works.

Well, life exploded a fair bit not too long ago, and I’m still slowly re-forming. I’ll facilitate this process by keeping the snarky, rambling, ego-stroking pontificating to a mini…

Ah, who the hell am I kidding? Read on…if you’ve got the stones.

GET IT?

Hm. Probably not.

I was going to fill this post with Twisted Sister lyrics – but my fire is faded and I can’t feel it no more. Instead, have some awful puns.

In my never-ending quest to more accurately reproduce a speculative Viking-era ale, it became “necessary” to reconstruct a Viking-era grain quern. This is the device that would be used to grind grain prior to being fashioned into “cakes” for subsequent use in beer production. I decided to make a mock-up using concrete, using an extant quern find as guidance. Volume 17 of the York Journal of Archaeology describes several quern finds. The majority are fragmentary querns from Mayen (a region in Germany) basalt, with the next largest group being gritstone (dense sandstone). Most finds lack any sort of “dressing” (grooves in the stone to aid grinding), and this seems to be common of Viking-era finds – dressed stones seem to be a post-Viking invention by and large.

I focused on find 9700, which is described on page 2628 at the above link. It’s a gritstone runner (upper) stone with a diameter of 35 cm and a thickness of 6 cm. It has a central perforation with a diameter of 7.5 cm.

I had difficulty getting a form that would give me a rock of the appropriate size, so I compromised. I cut the top off of a 5 gallon Lowe’s bucket (~12″ diameter) and used that as the form. I used Quickrete and cast a stone 30.5 cm diameter, 7.5 cm thick, with a central perforation ~4 cm in diameter. After accounting for the volume loss due to the central perforation, this wound up being pretty close to the same volume of stone as find 9700 (~5.4 L vs. ~5.5 L for the original find). Assuming that the base stone would have been approximately the same size (as seen in this Jorvik museum piece), it was cast with similar dimensions (though without quite the same amount of central perforation). In order to seat the spindle (wooden peg around which the upper stone turns) correctly, I simply jammed a length of wooden dowel about halfway into the base stone while the concrete was still wet.

There’s a joke in there, but I’m too classy to make it.

This even looks kinda vulgar, if you’ve got a warped imagination.

Grain is fed into the central hole of the runner stone (that’s malted wheat in the picture above), and the handle is turned in a circular motion to grind the grain. The upper stone travels in a mostly elliptical path, pushing the grain out from the central hole into the broader surface area between the two stones.

You can see from the pile in the above picture that the upper stone sort of “floats” on a pile of grain. As the handle is turned, that pile shoots in between the two stones, which gradually grow closer together as the grain is ground down. Grind down too far, and the stones make significant contact – making your job that much harder. Of course, the increased friction between the stones seems to grind a finer flour, so it’s a constant balancing act.

That was almost clever.

There is a “rhythm” to using the stones – turning the handle while periodically feeding grain into the central hole. Once the stones are “primed” with some grain, and as long as there’s always a central pile of some sort, the upper stone turns fairly readily.

“Fairly” is a subjective term, of course. I’m still basically rubbing a 25 pound coarse rock against another 25 pound coarse rock, and that takes some effort. After about an hour and a half of grinding grain and separating coarse material, I had ~2 cups of flour and a good sweat. Quite the forearm workout.

Note: Viking women are srs bsns. Do not anger them.

So what does the flour look like?

On the left, you can see both ground and unground malted wheat. The flour you see there is the result of a single pass through the stones. Not bad! Definitely some coarsely-ground material in there, but there is also quite a bit of flour.

On the right, we have some barley that I malted. That flour has been generated by grinding the grains 3 times (as in, re-grinding the product of the stones multiple times), and then bolting (sifting) the flour through a single layer of cheesecloth. As you can see, the malted barley flour has a somewhat sandy texture, but there is a good proportion of fine flour as well. Not pictured is the coarse material that was left behind after bolting – there was at least as much of that as the fine flour.

In retrospect, three passes seems unnecessary. Pass 2 and Pass 3 seemed to produce roughly the same consistency of flour, indicating that there is an upper limit to the fineness that can be generated in a mixture prior to separation of the flour. My speculation is that grain would be ground twice, bolted, and then the coarse material remaining would be fed back into the stone for another pass.

The resultant flour is also very “gritty,” as the action of grinding also loosens some grit from the concrete. I only let the stones cure for a week, which allows concrete to achieve ~60% of its final strength. Even then, concrete has similar physical properties to sandstone, which is noted by the Jorvik museum to add grit into the flour it generates. Most Viking-era quern finds are basalt, which is considerably harder; it’s conceivable that harder stone produced a less gritty flour. I’ll figure that out once I can get a line on some basalt.

My speculative brewing method involves rendering the malt into “cakes,” reflecting a malting method documented in the early Irish Senchas Már (which discusses “tests” of the malt made before it is “made into cakes”). After mucking about with the grinding stones, it seems that this was probably a necessary consequence of the method of grinding. The grain is ground much finer than we typically grind for mashing today, and excessive grinding can cause problems in conventional mashing setup by impeding the flow of wort. It’s also easier to transport and store cakes than it is to store loose grain or flour, so this really just seems to make sense.

Flatbreads or dung cakes? You know what, let’s just skip that question and sail somewhere that isn’t a frozen volcanic hell.

Even the “fine” flour seems to create a coarse bread. The bolting wasn’t as efficient as I’d have like; some husk and larger coarse bits did make it through. This is consistent with Viking-era “bread” finds, though, so I don’t think I got it “wrong.” It’s also worth noting that these breads are gritty. Like a mixture of tasty grain and sand.

What? Of course I put it in my mouth.

There is a lot of speculation that Viking toothwear patterns may have been the result of grit in their bread. After trying this out, I can see how that’s a plausible scenario. Of course, I also speculate that many breads were used for making a beverage rather than being eaten outright. Perhaps softer stones made malt cakes and harder stones made bread flour, or perhaps a Viking would eat bread until his teeth were bad enough that he’d need to drink it instead. Or maybe the toothwear comes from something else. There are many possible scenarios that can be constructed from the same evidence, so there probably wasn’t a “one true way” of doing things.

For the sake of experimentation, I went ahead and “mashed” some of the cakes to make a beer:

I’ve revised my “beer” recipe, and I think I’m happy with it now. 1 part of crushed malt cake is mixed with 4 parts cold water. This mixture is heated slowly until it’s just shy of boiling, and then the liquid is drained off. Mixed with that is 1/2 part honey, and some fruit if so desired. In this case, I tossed in some dried juniper cones in the mash (to give a bit of a juniper flavor), and used dried cranberries as a fruit additive once everything was mixed.

My reasoning behind that is the gloss between “beor” and “hydromel.” Most “hydromel” recipes that I can find around the time are a 1:4 honey:water ratio that is fermented for a short time. Such a ratio produces a fairly sweet beverage (for the brewers, an OG around 1.095), so my goal was to replicate that sweetness. 1 part crushed biscuit contributes roughly 40% of the needed sugar content, and removes roughly half its volume via absorption. Add in the lost volume as honey (hence half a part), and you also make up the other ~60% of needed sugar. Funny how these things work out, eh?

Interestingly, all of the grit in the bread seems to have settled to the bottom during mashing and formed a thick wet layer of clay-like grain/grit material. Perhaps making the gritty bread into a liquid was also a method of “cleaning” the bread of its gritty material? The stuff pretty well stayed put as I was separating the liquid, and there was quite a bit of stone grit left behind in the pot.

In the picture on the right, you can see the result of the mixture after ~3 days of fermentation. In the mason jar is my “ealu,” revived from a previous batch using 2 small grain/flax “crackers” (remember those?) and 3 cups of water; the stuff was fermented overnight, and then some of the dregs were used to start the beer. After ~3 days of fermentation, the beer is still pretty sweet, nicely bready, a bit fruity, and somewhat alcoholic. Not bad! Exceedingly pleasant!

So what next? I’ve been poking around at my recipe and production method in light of Dr. Pat McGovern’s grog paper; in particular, the heat-treated tree resin finds imply to me a processing method that involves localized high-intensity heat being applied to a solution containing suspended tree resins. He suggests a birch syrup production method, but I find that unlikely given the lack of evidence to support such a thing. I’m working on a method inspired by Finnish sahti brewing that turns the kuurna (hollowed-out log bedded with juniper branches) into a mash tun that is heated by hot rocks. Hypothetically, one could bed a hollowed-out log with evergreen branches, fill it with water and malt cakes, and plop in hot rocks until the temperature is right. The rocks may provide sufficiently intense localized heat to produce heat-treated tree resins. Let it cool, run the liquid into a vessel where you add honey and fruit, toss in some dregs from your magic bucket, and wait a few days.

That will have to wait till it warms up a bit more and this snow gets out of the way. In the meantime, I guess I’ll just sit here and play with my rocks.

As you will remember, I’ve been screwing around with Viking-era salt production methodology. Based on a review of the language and literature, scant archaeological evidence, and good ol’ fashioned guesswork, I’ve been cobbling together a method that involves steeping kelp ashes in water in order to extract their mineral essence. That link back there is proof-of-concept. It can work, at least in principle. Cool, right?As a scientist, I’m never satisfied with an answer. Ever. It’s kind of like the Creator’s Curse, in a way – in the process of investigating a hypothesis, we learn things that often cause us to alter our understanding of that hypothesis. Rarely are you “right” at the outset. More often than not, you’ll be confronted with how the magnitude of how little you actually knew at the beginning – because you’ve gained knowledge in the process.

So we’re doomed to keep asking questions about things we’ve already investigated over and over again, because dammit we just keep learning new things.

Knowing that it’s possible simply isn’t enough. I need to know how well the method works. Is it actually feasible at a production level? Would it make sense from a fuel consumption standpoint? How hard is it to pull off? What kind of product is left behind? These are all things that we can investigate through experimentation and review, and that’s what I’m starting on here. Investigation! Skeptical inquiry! Lighting shit on fire! All the best aspects of science!

Bro, do you even science?

In order to investigate plausible extraction methodology, I wanted to test two different factors: water source and heat of extraction. Previously, I simply soaked charred kelp in room-temperature water and boiled the runoff. That’s great, but we also know that the solute holding capacity of water increases with temperature – so hypothetically, a hot water extraction should allow more salts to dissolve than a room-temperature one.

I also used water from my tap, which is all good and well – but this is a utility endeavor, and it was practiced on beaches isolated from major population centers. Would a salt-karl really haul fresh water from somewhere just to make salt, or would he use the seawater that’s right next to his setup? Remember, Pliny indicates that many cultures (including various Germanic tribes) made salt by evaporating seawater, and some by pouring it over the hot coals of wood. It’s plausible that seawater plus ashed kelp could be used to produce a salt; Atlantic seawater is only 3.5% salt in composition, and the saturation point for a saltwater solution is around 26% (barring any hypersaline water oddities).

Before I could do anything, though, I needed to burn some shit.

For a dude who writes about Viking stuff, you’d think I’d have more pictures of things on fire.

As I’ve mentioned before, I bought 50 pounds of Icelandic kelp meal some time ago. Since then, I’ve been trying to figure out a way to effectively burn the stuff. The configuration makes it useless as a fuel item; a friend had suggested burning it as food, and even offered up the above-pictured Lodge cookware for it. The test-run many moons ago was successful but stinky – I figured my 60,000 BTU propane burner could get the job done.

Man, did it ever. My previous efforts never resulted in significant combustion, but this stuff really took off after the initial heavy smoke phase. Interestingly enough, it also burned out and never re-ignited; my guess is that most of the carbon content burned off, leaving behind mostly mineral salts. The fire itself produced a fairly noxious-smelling black smoke, with a chewy oily texture.

Let me just reiterate how awful this shit smells. It’s extremely smokey, takes a while to burn off (I think the pot above smoked for 45 solid minutes before catching fire), and smells like a rotting whale carcass stuffed with fermented shark that is also on fire. Also the whale is on fire. Also the entire ocean is on fire.

It’s really not pleasant.

Seems there’s a good reason that “salt-karl” was an insult, and why the Norse did this on a beach well away from other people. When I came in after 3 hours of burning stuff (during which I reduced 12 lbs of kelp to ~5 lbs of ash), my fiancee could only say “UGH. What’s that smell?” And today, two days later, my peacoat still reeks.

You could smell it at the porch, and 1/4 mile into the woods down our walking path. Also STANDING NEXT TO IT FOR 3 HOURS.Man, if only we could BUY salt or something.

So after I finished standing outside freezing my ass off while inhaling fumes of unknown toxicity, I had a tub of charred stuff that smelled fairly awful. It needed to cool overnight before it could really be useful – ashes tend to stay warm for some time. They never fully ashed, not even when combusted – but again, I believe that to be a byproduct of the configuration. Future experiments will look at trying to use sheet kelp as an actual fuel source, rather than expending heating fuel to make ashes.

Once you’ve got cooled kelp ash, it’s time to extract the mineral content! I’m used water as an extraction medium, and tried both conventional tapwater and a seawater analogue consisting of 3.5% salt.

It’s always prudent to assemble your materials before you proceed with an experiment. Here, I’ve procured my kelp ashes (~2.35 kg), propane burner and propane (set to 50% maximum output), several measuring containers, a strainer and bowl, and of course a kitchen scale.

The faux seawater solution was prepared by combining 5 kg of tapwater with 175 g of kosher salt, giving a final salt concentration of ~3.5%. Note that I weighed the water as opposed to measuring volumetrically – that’s because water has a density of 1 gm/cm^3 (until it gets near freezing, at least), so that 1 gram = 1 mL and 1 kg = 1 L. Convenient! My scale has better resolution (minimum 1 g) than my volume equipment, so this will allow for maximum accuracy.

Controls are crucial in any experiment, and it’s important to identify needed controls at the outset of an experiment – let your hypothesis govern the choices. In this case, I’m specifically looking to assess the difference in extraction efficiencies between 1) salt and fresh water and 2) low-temperature and high-temperature extractions. Because I will ultimately be measuring a mass of solid product, it’s important to know what will be contributing solids to the extracts. In order to provide controls, I boiled down 1.5 kg each of tap water and “seawater” and measured the mass of residue that could be removed from the pan.

On the left, you can see the residue remaining from boiling off tapwater. We’ve got hard water here (perfect for brewing), so it’s not surprising that there is a scale left on the pan. However, it proved to be too little to effectively harvest or measure, failing to register any mass on my scale. Thus, 1.5 kg tapwater contributes less than 0.5 grams of solids to final counts. On the right, we see the residue of the “seawater,” representing the base contribution to the method as well as accounting for the losses that invariably occur when trying to harvest the salt.

1.5 kg of saltwater with a concentration of 3.5% salt by weight yielded a final salt load of 46 grams. Hypothetical yield was 52 grams, but some salt was lost in processing. Still a fairly efficient extraction. The salt was initially rather wet after drying – something like 70 grams and a consistency not unlike brown sugar – but it was heated in the microwave for 1 minute to fully dry.

For sample setup, I basically drew a Punnet square and did the appropriate combinations. 4 500-gram portions of kelp were measured into appropriately-labeled dry containers. 1.5 kg of either salt or fresh water was added to each sample. Two of the samples (one fresh and one sea) were left to steep at room temperature for 30 minutes, while the other two samples (fresh and sea) were heated in a pot on the kitchen stove. Heated samples were brought to a visible boil, and dropped to a simmer for 5 minutes after the first bubbles breached the surface. Following all extractions (whether heated or room temperature), the water/kelp masses were strained through a wire mesh strainer, and the liquid phase collected. The kelp mass was allowed to drain for 5 minutes, ensuring collection of a significant portion of the liquid.

I didn’t measure the volume of runoff from each (though now I’m wishing I had) since I was only focusing on final solid extract generated by the methodology. However, all 4 extract methods appeared to produce roughly the same volume of runoff – roughly 400 – 500 mL. Future experiments will more accurately determine runoff volume generated by these extraction methods.

Once extracts were obtained, they were boiled down as the controls were. The pan was washed and dried in between each boiling (actually, all common equipment was thoroughly cleaned and dried in between samples to eliminate the possibility of cross-contamination), and the same equipment was used to extract the salt from the pan (i.e. a spoon and a spatula). Extract mass was determined using the same scale used to measure all of the ingredients. In order to standardize the moisture level, all samples were microwaved for 1 minute after collection as the saltwater control was.

I devised an abbreviation scheme to represent the four sample configurations. All samples are identified by three consecutive letters indicating their combination of treatments: K/[R or H]/[F or S], indicating [K]elp, [R]oom-temperature or [H]igh-temperature extraction, and [F]resh or [S]altwater extraction. Top row from left to right shows the solids extracted from KRF and KRS; bottom row from left to right shows extracts of KHF and KHS.

Yields for all samples and controls are given below. Compounded uncertainty in measurements is +/- 1.5 g; the scale has no listed uncertainty of its own, and 10 consecutive weighings of identical volumes showed no deviation. Uncertainty is thus half the value of the smallest unit of measure (1 g), added for each step that involves weighing. In this case, 3 different weighings of different components were used to determine the components of the extraction process – their uncertainties add together.

Sample NameMass of Extract (+/- 1.5 g)

Saltwater control 46 g

Freshwater Control <0.5 g

KRF 42 g

KRS 112 g

KHF 90 g

KHS 120 g

The results are not terribly surprising. Both of the hot water extractions yield more salt content than the lower-temperature extractions. The difference is greatest when using fresh water for the extraction, which indicates that the charred kelp contains quite a lot of salt to potentially extract. It is curious that the yield from KRS is larger than [KRF + Saltwater]; one would expect that the yield would simply be additive and thus the two would be mostly equivalent.

It appears that the high-temperature extraction with salt water yields the largest quantity of salt, but the gain from heating is minimal compared to a simple room-temperature salt water extraction. It appears that the use of salt water for extracting leads to the greatest gains in salt yield. This is unsurprising, as the salt water contributes a significant salt portion. It may be that the addition of charred kelp to salt water allows the solution to approach saturation; assuming 500 mL of final volume, the KHS solution would have had a solute concentration of ~24% prior to boiling.

Recovery efficiency seems to decrease as final salt mass increases. When evaporating KHS, several larger globs of salt “popped” out of the pan in response to heating. This phenomenon was observed in other extracts, and is generally exacerbated as the amount of salt condensing increases. This may also account for the observed decrease in effectiveness of heating in extracting additional salt from the kelp.

Ultimately, this demonstrates the utility of using kelp ash to increase salt yield from boiling seawater. 1.5 kg of seawater, when boiled off, yields 46 g of salt. The addition of kelp ashes to that same mass of seawater, while reducing final liquid volume, can increase the final salt yield by a factor of approximately 2.5, for a maximum yield of 120 g. This has the potential to consume less fuel (boiling a smaller volume of liquid) while simultaneously increasing salt yield.

It should be noted that expending fuel specifically to ash the kelp is likely a fuel-losing prospect. More than likely, sheets of dried kelp were themselves burned as a fuel source, and the ashes collected and used for various home purposes.

The standard for food grade salt is 500 ppb total arsenic, so this slightly exceeds that. However, they also note that marine products (seafood and kelp) routinely have higher levels of arsenic (mostly organic, with ~1 – 3% as inorganic), often up to 50 mg/kg (50,000 ppb).

A 2007 study by Amster et al raised some concern about arsenic in kelp supplements, but was highly criticized because it failed to speciate the arsenic, and thus could not demonstrate the toxic link it claimed. The paper also suffered other severe methodological flaws.

In general, the amount of arsenic observed in the salt is not of concern. 10 g of the salt (twice the RDA for sodium) would contain 5 ug of arsenic, well within the typical human daily consumption range. And it is unlikely that all of the arsenic is inorganic – most is likely the organic (non-toxic) form, rendering the salt largely non-toxic.

But I would not use this salt as a day-to-day table salt, to be on the safe side. As a preservative for fish which is likely to be soaked out, it should be fine.

Thanks to Tom King and the chemistry division of the NYS Department of Agriculture and Markets Food Lab!

So now that I’ve got a prospective method and ingredients list cobbled together, my next phase will involve passes at more accurately re-creating the tools and ingredients that may have gone into making a Viking-era beer.

First up: the malt.

Malt is at the heart of beer brewing. Grains are allowed to partially germinate, and are then heat-treated to stabilize them and enhance their flavor. Depending on the grain, the method of malting, and the method of kilning, you can wind up with a great variation in types of malt, which is turn greatly influence the characteristics of the final product.

The Senchas Már contains requirements for the production of malt, and I’ve speculated that cultural contact between the Irish and the Scots could create a plausible route of transmission to the Norse. Most large cereal kiln finds from the Viking era exist in Scotland, so it seems plausible that it was a center of production.

Typical fuels excavated from such kilns include local hardwoods, plant matter (sometimes peat), and occasionally dung. Dung is more commonly seen in Icelandic farm mound excavations and other fire pits; an analysis of one such farm mound revealed charred wood and dung alongside charred 6-row barley seeds – the presence of all 3 in the same layer may indicate that their use was concurrent.

Icelandic finds rarely include the larger kilns seen in Scotland. However, the principle of drying over a fire is pretty constant throughout processing technologies – and given that my current model involves a gradual transition from home production to quasi-industrial production, it makes sense that an Icelander may have used a conventional cooking fire for malt drying earlier in the era. It seems plausible that some extant structure in the Icelandic finds pulled double-duty.

The tradition of drying grain over a fire persists in Scandinavian homebrewing to this day, and is expressly documented in Olaus Magnus’ 16th century writings. It seems possible that we may be viewing a sort of living tradition, though I am always skeptical of such things.

So with all that in mind, let’s light some shit on fire.

They probably didn’t do this when it was below zero outside, but screw it – there’s beer on the line.

Up here in New York, the ground is currently frozen solid, which makes constructing an in-ground malting kiln somewhat…challenging. Also, it’s fairly cold up here at the moment, so the prospect of chipping away at frozen earth so I could put a fire in it seemed…well, pretty fucking dumb.

I mean, when it was cold in Viking-age Iceland, they stayed inside. Where it was warm.

So instead of trying to replicate the thermal properties of the kiln/oven (which will come later, when the ground isn’t a block of ice), I opted to try out the notion of directly drying the malt over a fire. I have a smoker, so I figured it would work well for this purpose.

This experiment will help me figure out the fire dynamics, and gauge the effect of a wood fire on the flavor and mash characteristics of the malt. A more elaborate kiln may very well have a different effect, but this will at least help me ballpark it.

First things first, ya gotta malt some grain.

Look at the little barleys, so fully of hope and life.Theirs is a sad fate.

I used a mixture of an American 6-row barley and steel-cut oats; the oats won’t malt, but they’ll add some grain bulk, and my hope is that excess enzymatic activity in the barley will have some effect.

The method outlined in Irish law takes a bit more than two weeks, but I opted for a very short malting time – partly because modern malting barleys germinate substantially faster than do heritage varieties. The barley in that picture is starting to show acrospire formation, and that’s only been going for 4 days – 1.5 days steeping and the rest of the time being turned in heaps.

I drained the grains a bit, and then set them on top of some aluminum mesh window screening material, to hopefully keep most of the grain from falling into the fire. The fire was started with a little bit of charcoal, but fed exclusively with dried hardwood and the occasional blast of Icelandic kelp. Dung and/or peat would be more accurate, but I have no dried dung and I wasn’t exactly going to go looking for it.

On went the grain, and then began the waiting.

This’ll be great! It can’t possibly take that long!

And the waiting.

And the stirring of the malt.

And the more waiting in the cold and the wind.

This is maybe half dried, and I should emphasize that I was pretty damn cold at this point.

And then I said “screw this, it’s too cold,” fed the fire nicely, stuck the lid on, and sat inside for a bit.

Once again, it’s almost like I know what I’m doing.

The action of the fire on the grain is interesting. The stuff dries fairly unevenly; as you can see, some of the grain is charred, some just very heavily roasted, some a nice chestnut color, and some a rich yellow hue. This is interesting, because it means that grain dried over a fire does not provide a homogeneous flavor profile; rather, several different “kinds” of malt will come together to make a richer flavor.

Some of the paler malt tasted a good bit like honey, rather akin to Gambrinus’ proprietary honey malt. That’s a result of grain “crystallization” (where the still-wet grain undergoes a mini-mash in the hull, and the sugars crystallize in the husk) and subsequent heat-based caramelization. Other grains are warm and nutty, and others are more like espresso beans.

What really struck me, though, is the complete lack of smoke flavor. The entire drying process took nearly 3 hours, and roughly 2/3 of that time had the grain being subjected to a fairly hard hot smoke. I did use a fairly clean-burning mild-tasting hardwood – but I still expected something to come through.

Nada. Not even a hint of smoke.

The really interesting part about that is that the Scottish kilns are designed to really minimize smoke intrusion, and also use a cloth (rather than aluminum mesh) to hold the grain. There should be even less smoke flvaor with that sort of setup.

The grain you see pictured is a little more heavily roasted than I’d like – a bit much char. However, I also learned that I have complete control over the rate of heating and drying – covering and uncovering the grain in conjunction with careful fire feeding lets me get some pretty solid temperature regulation. The next time I do this, I think I’ll have a better sense of how it works.

Next time, I’m going to play around with a prototype grain quern, to figure out how this kind of stuff may have been ground, and what it would be like.

A mid-cycle update?! Madness! Pandelerium! Falling skies and cohabitating felines and canines and other social currency references!

Several people have pointed me at some very recently published research coming from Dr. Pat McGovern regarding Norse brewing. If you’re a nerd like me who is conversant with science, the paper is available for free from the journal – ain’t open access grand? McGovern’s analysis of biochemical residues reveals that the ancient Danes may have drunk a concoction of honey, grains, local fruits (cranberries), possibly imported grapes, and local herbs.

But who’s counting, right? Certainly not I. Truth be told, I was not the first person to come to that conclusion; Ian Hornsey reached a similar conclusion in 2003 in his book A History of Beer and Brewing.

Until now, the primary issue in figuring out Viking-age booze was the small matter of a near-complete absence of physical or written evidence. No finished product has been recovered, no obvious brewing facilities have been found, and few pieces of ancillary equipment exist. In addition, there is no written method documenting any alcohol production by the Norse – they weren’t a writing-centric society, and even the few written works that do exist don’t bother with something as simple as alcohol production.

My research pulled together linguistic, literary, and indirectly-related archaeological evidence to build a plausible paradigm for Viking-age brewing – including figuring out what ingredients may have gone into it.

McGovern’s findings represent the first complete physical evidence pointing to actual ingredients that may have plausibly been involved in producing Norse alcohol – and that evidence completely supports the hypotheses I’ve been developing for over a year now!

Now, granted, the time period of his findings pre-dates the age of the Vikings – but my current research combined with this new evidence makes a very compelling case for its continuation. In addition, the presence of multiple sugar residues in a vessel is not de facto evidence that all of those were mixed into the same beverage – but considered in conjunction with my research, the case is certainly strong that it was probably being done. And the residue evidence is still not evidence of any particular processing technique – so the paradigm and processing research I’ve done is still fairly speculative.

Really, it’s the processing and goal that matter the most; a brewer could technique a set of ingredients and produce several radically different beverages simply by altering his processing technique. The question is then: what are you trying to accomplish, and how can you accomplish that?

Some of the evidence recovered by McGovern does help tie into the processing methods that I and others have begun to reconstruct. For example, one of the analyzed residues contained evidence of resins derived from birch and pine. I had previously speculated that wooden vessels were likely used as both mash tubs and fermentation vessels – they may have even been used to store finished product for a time. I’ve speculated that a birch and fir vessel may have been used to ferment some part of this product – an excellent avenue for dissolving tree resins. Merryn Dineley has worked on reconstructing mash houses using wooden troughs or vats and hot stones – depending on the wood, the hot water will extract various resins with great efficiency. Either of those methods could account for the presence of the tree resins in McGovern’s findings.

The evidence regarding the presence of grape sugars is also particularly interesting, as it constitutes the earliest evidence of the fermentation of the grape in northern Europe to date. It shows that ancient cultures were trying to – and able to – get their hands on the grape for a long long time. It’s most likely that grapes were still comparatively rare in Denmark and farther north – so their inclusion likely represents a person of wealth and status. It also helps reinforce the cultural parity between these ancient strong drinks and wines – occupying the same cultural purpose, it makes sense that they would perhaps share ingredients when possible.

So I’m excited! Largely because dammit I was right. It’s always good to get solid evidence confirming a speculative hypothesis.